1. Field of the Invention
The present invention relates generally to fastener retainers and, more particularly, to a convoluted fastener retainer for maintaining a fastener having an extending shank within a bore provided on a structural member.
2. Discussion
Manufacturers are constantly striving to increase productivity by reducing assembly time during the manufacturing process. It is known in the art to streamline manufacturing by pre-attaching fasteners to structural members which are later used in the assembly of a component.
U.S. Pat. No. 3,083,796, which issued on Apr. 2, 1959 to Bell, discloses a rigid annular sleeve including inwardly extending fingers which is disposable over a fastener shank. The fastener is inserted through a bore contained on a bracket and the sleeve is then disposed over the fastener shank whereby the inwardly extending fingers engage the fastener threads and fixedly hold the sleeve relative to the fastener. The fastener is thereby secured on the bracket by the annular sleeve and subsequently applied to second member through a threaded opening. The sleeve must be interposed between the two members, however, to maintain them in spaced relation, and therefore the annular sleeve is not suitable for use in most manufacturing applications. Thus, a bolt retainer operable within a conventional bore is still needed.
Assembly times may also be improved by providing a means to more easily align the fastener with a corresponding bore on a second component which may or many not be in axial alignment with the central axis of the first bore. U.S Pat. No. 3,008,368, which issued Nov. 14, 1961 to Hammitt et al., discloses an annular sleeve slidably inserted over a fastener shank whereby, upon tightening the fastener, the exterior surface of the aligning device engages the wall of the bore extending through the first surface. A lateral force is thus produced which tends to push the first surface away from the fastener at the point of contact thereby aligning the bores.
Additionally, U.S. Pat. No. 5,141,357, which issued Aug. 25, 1992 to Sherman et al., discloses a similar apparatus designed to align fasteners within tapered bores. A cone shaped outer body having an eccentric cone shaped aperture extending therethrough is disposed within a tapered bore. A cone shaped inner body having an eccentric cylindrical bore is then positioned within the tapered inner bore of the outer body. By rotatably adjusting the outer and inner bodies relative to one another, the cylindrical bore is aligned with a bore on a second surface.
Neither Hammitt nor Sherman, however, provide a device disposable within an axial bore which allows the fastener to be simultaneously tilted and laterally shifted within the bore in order to achieve alignment with a bore on a second member. Sherman is disposable within a bore, but does not permit the fastener to tilt away from the central axis of the first bore. Conversely, Hammitt permits the fastener to be inserted into a nonparallel second bore but must be disposed on the fastener shank prior to fastener insertion.
Accordingly, it would be desirable to provide a retainer which both maintains pre-attached fasteners within a bore and permits the fastener to shift within the bore in order to achieve alignment with a second bore. The retainer must be disposable within a bore and capable of maintaining the fastener along the central axis of the bore in the absence of external forces. Additionally, the retainer must yield to selective translational and/or rotational movement of the fastener shank within the axial bore. Thus, the primary object of the present invention is to provide such a retainer which will further increase manufacturing productivity.